Welcome to GTV!
Today I will be installing an Under-voltage Release, or UVR unit, in an ABB Tmax series
T1, T2, and T3 enclosed circuit breaker.
These circuit breaker accessories should only be installed with the breaker out of circuit
or when all power has been removed from device, control panel and anything nearby that may
be a hazard to the qualified electrician doing the installation.
This UVR kit includes the UVR unit, a mounting screw, a spacer, an installation tool, and
device labels.
These are the T1, T2, and T3 circuit breakers.
To install the UVR unit, I will need to set the circuit breakers in the test position
by switching the breaker to off, then on, and then by pushing the test button here.
Once they are in the test position, I can remove the screws and take off the front plate.
As you can see the T2 model has a protective cover where this accessory will go.
This cover is not present on the T1 or T3 models.
To remove the cover, I will pull on the top of the protective cover outward and downward
until it is free from the frame.
This cover will not be used after the UVR is installed, so I will set it aside for recycling.
Next, I will remove this side cover where the wires will be routed.
It is easily done by sliding it in the grooves toward the front of the breaker until it is
released.
I will reinstall this in a moment, so I will set it aside for now.
Before installing the UVR unit, it will need to be preset, meaning that the spring action
of the mechanism will have to be held back into position to allow for proper installation.
I’ll accomplish this by holding down on the mechanism in the UVR with my thumb, while
holding it in one hand.
With my other hand I will temporarily install the installation tool like this, which will
hold the UVR mechanism in proper position for installation.
I will install the UVR in the breaker by inserting this actuator tab into this opening at the
back of the accessory port while aligning the hole in the UVR’s mounting tab to the
mounting hole on the frame.
During the installation, I carefully make sure that the wires are routed in the narrow
gap in-between the UVR unit and the inside of the circuit breaker frame.
During the installation, I feel slight resistance of the trip mechanism’s spring tension pushing
the trip unit out of position.
So, I keep pressure here with my thumb while fastening it with the screw.
When holding the UVR unit in place, the installation tool may become loose and fall out.
This is acceptable providing that the UVR unit is being held in place by hand until
it is fastened to the circuit breaker’s frame.
Once the UVR is installed, the installation tool will no longer be needed.
It may be kept for future servicing of the UVR and breaker or it may be set aside for
recycling.
The trip unit is properly installed when I can see that the back of the trip unit is
mounted flush with the back of the accessory port.
A step that is exclusive to the T3 model is the installation of this spacer, which is
not required on the T1 or T2 models.
I will insert this spacer to the right of the UVR unit.
The wires should be routed along the wire channel on the outside of the circuit breaker
frame.
The wire channel cover can be shortened so that the wires can exit the channel right
at the surface of my enclosure panel when the circuit breaker is surface mounted.
To shorten the cover, I’ll bend it back and forth here, where it has been pre-scored
and notched by the manufacturer, until the part separates.
Then the wire channel cover can be slid back into place.
Now I will reinstall the front cover and fasten the screws to the frame.
Finally, I will apply the legend decals on the side of the breaker for future reference.
I can now have a qualified electrician install and test the functionality of my circuit breaker
and UVR unit.
This completes the installation of the UVR to the Tmax series of circuit breakers.
To find out more about this product and its accessories, please check out our other videos
on GTV.
ABB’s Tmax series Accessories, along with thousands of other products and services are
available at galco.com.